Self-leveling foot structure



F. C. BONTECUE SELF-LEVELING FOOT STRUCTURE Filed Nov. 15, 1957 July 12, 1960 2,944,367

INVENTOR: FREDERIC C. BONTECU 2,944,367 SELF-LEVELING FOOT STRUCTURE Frederic C. Bontecue, Chicago, Ill., assignor to Plastic Precision Parts Co., Chicago, Ill., a partnership Filed Nov. 15, 1957, Ser. No. 696,706

4 Claims. (Cl. 45-139) 7 This invention relates to a foot structure especially adapted for use with table model appliances such as recorders, record players, radios, etc. and more particu-' larly to a self-leveling foot construction and system Support surfaces such as table tops, benches, stands, etc. upon which appliances are generally placed fre-' qucutly have slight irregularities therein so that an appliance placed thereon does not have a solid footing and as a result may be tipped or rocked slightly. For example,

if an appliance has a foot pad at each of four corners, and the support surface is slightly elevated under one of such pads, then substantiallyall of the weight is carried by two of the foot pads thereby permitting the appliance to be rocked between the remaining two pads. Such a condition is always undesirable and in certain instances poses particularly serious problems. A record player may be cited as an example. Even the slightest rocking thereof is often sufficient to displace the reproduction needle several grooves on the record tablet. Consequently, portions of the record would not be reproduced, and, even more seriously, the record would be scratched by such displacement and therefore permanently damaged.

Adjustable foot pads are known but have not proved satisfactory for it is extremely difficult to accurately adjust for positioning each of the foot pads so as to equally divide the total weight of the appliance thereon. In the absence of such adjustment the appliance will not have a stable footing. Furthermore, manually adjustable devices are of necessity relatively expensive and require the attention of the user of the appliance. Such attention is ordinarily not forthcoming. .Three point support leaves a rectangular cabinet unsupported at two stand or'any other suitable surface sufliciently strong to corners.

It is also known that self-leveling foot structures have been employed in the past and perhaps the most wellknown are the compressible fiber and resilient rubber pads. Fibrous pads are not satisfactory for a permanent deformation of the pads occurs and thereafter these pads are useless if the appliance is shifted to a new location. Rubber pads have the advantage of restoring themselves to their pre-stre'ssed condition when the weight of the appliance is removed therefrom but have the disadvantage of yielding andcausing theneedle to bounce if the cabinet is struck and also of marking'or marring the support surface, especially if the rubber is soft or spongy. Very often portions thereof adhere'to the surface.

It is accordingly an object of this inventiontoprovide a foot structure which will overcome the disadvantages inherent in the prior art devices. Another object of the invention is in the provision of a self-leveling foot structure characterized by automatically adjusting toslight irregularities'in a support surface to the end that a plurality of such'structures afford a stable or solid footing United tfo 2,944,367 Patented July 12, 1960 v 2 for an appliance equipped therewith and which has the additional advantage of self-restoration or recovery when the weight of the appliance is removed therefrom with the result that the self-levelingfunction isrepetitive and occurs each time the appliance is moved to -a new location.

Still another object is that of providing a self-leveling foot structure that resists deformation and which slowly but firmly deforms to the extent necessary to bring each of the foot pads of an appliance equipped therewith into engagement'with a support surface therefor to thereby afford a stable or non-rocking footing therefor. A further object of this invention is toprovide a foot structure of the'character described having a hollow sleeve engageable with a support surface at one end thereof and equipped with a web extending transversely thereacross provided. with a boss extending"upwardly therefrom above the upperedge of the sleeve for securing to the under surfaceof 'an' appliance; the foot structure being made. of virginpolyethylene and the web thereof being dimensioned so as 'to provide a resistance-to deformation related to the expected proportion of an appliance 'weighttobe' supported thereby so that substantially no deformation of the web occurs when such expectedweight is in fact borne thereby but which does deformin direct ratio to weight in excess thereof. Additional objects and advantages will become apparent as the specification develops.

' An embodiment of the invention is illustrated in the accompanying drawing in which:

Fig. 1 is a side viewin elevation of a record player equipped with foot structures embodying the invention and in which the support surface for the record player is shown insection;

Fig. 2 .is an enlarged broken side view in elevation of a corner of the record player shown in Fig. 1' but in which the foot structure is illustrated in section; and

Fig. 3 is an enlarged broken side view in elevation of another corner portion of the record player and in which the foot structure thereof is shown in section.

The self-leveling foot structure of this invention is suitable for use with numerous appliances and the record player case is an exemplification thereof. Insofar as concerns the instant invention therecord player case may be wholly conventional and is seen to have a casing Y 11 equipped with a hinged cover 12 adapted to be anchored in closed. relation with the casing by means of the clasps 13 and 14. The record player shown is a portable unit and therefore is provided with a carrying handle 15. The record player is positioned upon a support surface 16 which may be a table top, a bench, a

support the weight of the appliance thereon. The support surface 16 is seen to be irregular and for purposes of facilitating a description of this invention such irregularities are exaggerated.

The record player case is generally rectangular and as the result is provided with four corners each of which is equipped with a self-leveling foot structure. For purposes of identification the two corners illustrated in Fig. l are designated with the numerals 16 and 17 and these corners are equipped respectively with foot structhe identical parts except that as applied to the foot 19, such numerals will be primed.

The foot pad 18 comprises a hollow sleeve or tube 20 equipped intermediate the ends thereof with a web 21 extending transversely thereacross and which in turn carries a boss adapted to abut the under surface of the casing 11. The web 21 and boss 22 are provided with an opening or bore extending centrally therethrough adapted to receive a rivet 23 which extends into the casing 11 and rigidly anchors the foot thereto. It is apparent that the head 24 of the rivet bears against the underside of the web 21 while at its opposite end the rivet is swaged or turned outwardly as shown at 25 to bear against the inner surface of the casing 11. The sleeve 20 is generally cylindrical but the diameter at the lower end thereof is substantially less than the diam eter at the upper end thereof whereby the outer wall 26 tapers downwardly and inwardly. The inner diameter of the sleeve 2% also varies incrementally therealong so that the wall of the sleeve is substantially thicker Where it merges with the Web 2.1 than at the'extremities thereof. Thus the inner wall 27 of the sleeve tapers inwardly and upwardly while the inner wall portion 28 thereof above the web 21 tapers downwardly and inwardly. However, that portion of the sleeve'defined by the wall section 27 is generally thicker than that section of the sleeve defined by the wall portion 28. Consequently, the sleeve is substantiaily'thicker along the underside of the web 21 than along the upper side thereof. 7 p a a The sleeve 20, web 21 and boss 22 are all integra and are formed of a material characterized by being mildly resilient yet relatively stiff and therefore substantially resistive to deformation of the web 21 under the normal weight applied thereto. On the other hand, the web 21 should be deformable when weights in excess of the expected load to be carried thereby are applied thereto. Further, the web should restore itself to its preloaded condition when the weight or load is removed therefrom. It has been found that virgin polyethylene provides these characteristics. If the foot is made of this material it may be a molded component. The relative weight borne and the deformation acquired is related to the thickness of the web 21 and this can be changed for dilferent applications either in the casting die or by subsequent machining.

Thus, the foot structure lends itself to design with reference to a given expected load to be carried thereby. If the appliance It is relatively light the foot need not be as strong as if the appliance It? is quite heavy. In the latter case the web 21, at least, would have to be substantially thicker so that it would be capable of carrying a heavier load without excessive deformation. Usually an appliance has the component parts thereof arranged so that each corner thereof carries substantially the same weight. Therefore, with an appliance having four corners, such as the one shown in Fig. 1, each of the foot structures may be designed to carry one-quarter of the total weight thereof.

To use the self-leveling foot structures one is secured to each corner of the appliance by the rivets 23 or other suitable means. Thereafter the appliance 10 may be placed on the support surface 16 and if such surface is perfectly smooth each foot will engage the same and will carry substantially one-fourth of the total weight of the appliance. Under such load conditions the web 21 of each foot will not deflect or distort downwardly or will do so only to a very limited extent for the foot is designed to carry its share of the weight of a particular appliance without substantial deflection. If a portion of the surface 16 is elevated as is the case under the foot 18 all of the weight of the appliance will tend to be carried by the foot 18 and the foot diagonally opposite thereto. As the consequence, the foot 19' and its diagonal equivalent will selectively carry none for only a small portion of the weight. Therefore, the appliance can be 4 rocked about the pivot points defined by the foot 18 and its diagonal equivalent to bring either the leg 19 or its diagonal equivalent into engagement with the surface 1K6.

However, since the foot structures of this invention are being employed the web 2.1 of the foot 18 and the foot diagonally oriented with respect thereto will commence to deflect downwardly because each of these feet will be carrying substantially twice the Weight for which they are designed. Such deflection will continue until the foot 19 and its corresponding foot are brought into engagement with the support surface. As soon as this occurs these feet begin to assume a portion of the total weight of the appliance and further deflection of the webs 2.1 of the foot 18 and its equivalent will not occur. The: after the appliance 10 will have a stable or nonrocking footing on the surface 16 for each of the four foot pads thereof will be in engagement with the surface.

Fig. 2- represents the configuration of a foot pad carry ing a load that is less than or substantially equal to the weight for which it has been designed to support. On the other hand, Fig. 3 illustrates the configuration of a foot pad subjected to a greater load than that for which it was designed. Fig. 3 also indicates the maximum deflection of the web 2.1 for the bottom wall of the appliance is shown in engagement with the upper edge of the sleeve 20 wherefore no further deflection of the web can occur. It should be noted that the deflection of the web may terminate and preferably does terminate before the appliance engages the tube 20. 'Therefore, the maximum range of adjustment of the feet occurs within that distance defined between the bottom surface of the appliance and the upper edge of the sleeve before the web has deflected as shown in Fig. 2. j

if the surface 16 is so irregular that all of the four foot pads of the appliance have not been brought into engagement therewith when one or more of the foot pads has deflected to its maximum extent as shown in Fig. 3, then a stable footing for the appliance cannot be attained at that location along the support surface and, of course, the appliance should be shifted to a new location. it will be apparent, however, that the maximum range of self-adjustment for the feet can be increased by increasing the height of the boss 22.

The self-leveling foot structures automatically adjust only to the extent necessary to provide a firm, solid footing for an appliance such as a record player of the type adapted to the position on a table top or equivalent support surface. The feet tend to resist deformation and therefore slowly deform when a load greater than that for which they are designed is imposed thereon. Yet when such load is removed from the feet they restore themselves to their initial condition and may again perform their self-leveling function if the appliance is shifted to a new location. While the feet are intended to accom modate only slight irregularities in a support surface it will be apparent that the design thereof can be varied, especially by increasing the height of the boss 22 so that the feet can be used with surfaces having even greater irregularities therein. Further, the feet can be designed so as to carry greater or lesser loads simply by changing the thickness of the web 21 or by altering the thickness of the sleeve 2% at the point of merger thereof with the lower surface of the web.

While in the foregoing specification a-specific embodiment of the invention has been described in considerable detail for purposes of making an adequate disclosure, it will be apparent that various changes may be made in such details without departing from thespirit and principles of the invention.

I claim:

1. In a foot structure of the character described adapted for use with record players and the like, a molded polyethylene foot comprising a hollow sleeve equipped intermediate the ends thereof with a wee extending transversely thereacross having a boss extend? ing upwardly therefrom to an elevationabove the upper edge of-the sleeve, said sleeve at the lower edge thereof being adapted to be positioned on a support surface and said boss being adapted to abut the underside of an appliance, said sleeve and boss being provided with a centrally disposed, longitudinally extending opening therethrough adapted to receive a rivet for securing the foot to such appliance, the cross-sectional area of said foot at the lower edge thereof being less than its cross-sectional area at the upper edge of said sleeve, the thickness of said sleeve being progressively increased from the extremities thereof toward said web and the sleeve along the underside of said web being substantially thicker than along the upper side thereof, said web being characterized by resisting downward deflection but being downwardly deflectable free of lateral compressive forces when a weight in excess of a predetermined magnitude is applied thereto, said web also having the characteristic of restoring itself to its pre-deflected condition whenever such weight is removed therefrom.

2. In a self-leveling foot structure of the character described, a hollow sleeve adapted to seat at one end upon a support surface substantially flat, a polyethylene or the like web of essentially uniform thickness extending horizontally across said sleeve, and a boss carried by said Web and extending upwardly therefrom above said sleeve at the center thereof for securement to the underside of an appliance, said web being characterized by being downwardly deflectable free of lateral compressive forces when a weight in excess of a predetermined magnitude is carried thereby but having the capacity to yieldingly resist such deflection and to restore itself when such weight is removed therefrom.

3. In a self-leveling foot structure of the character described, an integral body of virgin polyethylene com- 35 2,602,616

prising a hollow sleeve adapted to seat at one end upon termediate the ends thereof, and a boss carried by said 7 a support surface, a web extending across said sleeve inweb and extending upwardly therefrom above said sleeve, said web and boss being provided with an opening extending longitudinally therethrough for receiving a rivet to mount the foot structure on the under surface of an appliance, said web being characterized by being downwardly deflectable free of lateral compressive forces which increase with deflection when a weight in excess of a predetermined magnitude is applied thereagainst but having the'capacity to yieldingly resist such deflection and to restore itself when such weight is removed therefrom.

4. In a device of the character described, an integral foot molded of a plastic characterized by being mildly resilient'yet relatively stiff and resistive to deformation and comprising a hollow sleeve adapted to seat at one end upon a support surface, a substantially flat web extending across said sleeve intermediate the ends thereof, and a boss carried by said web spaced from said sleeve and normally extending upwardly therefrom to a point above said sleeve, said web and boss being provided with an opening extending longitudinally therethrough for receiving a rivet to mount the foot structure on the under surface of an appliance, said web being downwardly deflectable when a weight in excess of a predetermined magnitude is applied in a direction transversely to its flatness but having the capacity to yieldingly resist such deflection and to restore itself when such weight is removed therefrom.

References Cited in the file of this patent UNITED STATES PATENTS 1,886,112 Luarde Nov. 1, 1932 Helmond July 8, 1952 2,719,017 Mordarski Sept. 27, 1955 

